(20 U.S.C. 6301 et. seq.), as amended by this Act, from programs. authorized under the Elementary and Secondary Education Act. of 1965 (20 U.S.C. 6301 et seq.), as in effect on the day before. the date of enactment of this Act.
The efficacy of a vaccine is different from its effectiveness. It is dependent on several factors such as: 1  adherence to vaccine schedules. 2  the disease â some diseases have vaccines against them that perform better than for other diseases. 3  the strain of vaccine â some vaccine strains are more effective than others.
Sometimes vaccines are called immunizations, needles or shots. Here's how vaccines work: 1  Most vaccines contain a little bit of a disease germ that is weak or dead. 2  Vaccines do NOT contain the type of germ that makes you sick. 3  Some vaccines do not contain any germs.